Design And Implementation Of Simulation Equipment For HF Radio And Channel

HF wireless communication has been widely applied in many fields due to its advantages of low cost,long distance transmission and hard to destroy.If the HF communication system and equipment is researched and tested in real HF channel,the costs and period will be greatly increased.Therefore,it is necessary to develop a HF channel simulator so that the HF communication system can be researched and tested indoors.The research content of this paper comes from the subject "The Simulation Equipment for HF Radio and Channel".The purpose is to develop a simulator that can simulate the remote control function of HF radio and HF wireless channel,so that the research of the third generation HF communication controller called "Intelligent System for Transceiver and Calibration through HF Dual-Frequency" can be carried out indoors.Above all,the characteristics of HF communication are studied.The software technology and hardware interface protocol used in the Intelligent System for Transceiver and Calibration through HF Dual-Frequency is understood.The implementation of some core functions is theoretically analyzed and verified,which prepares for the Design and Implementation of a Simulation Equipment for HF Radio and Channel.Then,based on the actual demand,start with the application scenarios of simulation equipment,the function settings and design requirements of the simulation equipment is analyzed.The overall design of simulation equipment and the system architecture is given.The design details of each part of the simulation equipment are introduced in detail.Some innovative solutions are adopted to solve the engineering practice problems in the process of embedded development.For example,in the part of HF radio simulation,the operations of different radio types are abstracted and encapsulated separately in separate radio type files,which simplifies the processing logic of multi radio support,enabling simulation devices to conveniently add support for new radio types.The timer is operated by the method of "Clock Picking",so that the monitoring of multiple timing tasks can be realized just through the cooperation of two timers.In the part of HF channel simulation,the AWGN of the specified SNR is added to the audio signal containing digital data using the way of DSP.In the part of system interaction,a synchronization protocol for data interaction between host computer and slave equipment is designed.Finally,the implementation of the Simulation Prototype Equipment for HF Radio and Channel are realized on the hardware platform based on STM32F767 chip.Its main functions include: receiving radio remote control signal from Intelligent System for Transceiver and Calibration through HF Dual-Frequency,simulating the process of the real HF radio remote control,processing and responding to the signal;according to the current channel status to determine whether to allow the channel to get through,if allowed to get through,it adds AWGN pre specified SNR to the audio signal transmitted in the channel;it can change system setup and synchronize data with the slave equipment through the host computer software;important system operation parameters can be displayed in real time through the display screen.The Simulation Equipment for HF Radio and Channel are combined with the Intelligent System for Transceiver and Calibration through HF DualFrequency to form an integrated test platform,and the function and performance of AWGN addition of the simulation equipment would be tested.The results confirm that the prototype equipment can reach the design specification.